chore: upgrade bridges + bridge DBs

signalbridge: v0.8.7 -> v0.2606.0 (calver scheme change, already Go-based)
telegrambridge: v0.15.3 -> v0.2606.0 (Python->Go bridgev2 rewrite; config template rewritten)
signaldb/telegramdb/discorddb: postgres 13-alpine -> 14-alpine (PG13 EOL; conservative one-major bump)
.env.sample: TELEGRAM_BRIDGE_PERMISSIONS relaybot -> relay (Go bridgev2 permission rename)

.env.sample

@@ -217,7 +217,7 @@ RETENTION_MAX_LIFETIME=4w
 #VERIFY_SSL=false
 #ENABLE_ENCRYPTION=true
 #TELEGRAM_APP_ID=
-#TELEGRAM_BRIDGE_PERMISSIONS="{ \"*\": \"relaybot\", \"@foo:matrix.example.com\": \"admin\" }"
+#TELEGRAM_BRIDGE_PERMISSIONS="{ \"*\": \"relay\", \"@foo:matrix.example.com\": \"admin\" }"
 #TELEGRAM_SYNC_CHANNEL_MEMBERS=true
 #SECRET_TELEGRAM_DB_PASSWORD_VERSION=v1
 #SECRET_TELEGRAM_API_HASH_VERSION=v1

compose.discord.yml

@@ -30,7 +30,7 @@ services:
       - internal
 
   discorddb:
-    image: postgres:13-alpine
+    image: postgres:14-alpine
     secrets:
       - discord_db_password
     environment:

compose.signal.yml

@@ -10,7 +10,7 @@ services:
       - signal-data:/signal-data
 
   signalbridge:
-    image: dock.mau.dev/mautrix/signal:v0.8.7
+    image: dock.mau.dev/mautrix/signal:v0.2606.0
     depends_on:
       - signaldb
     configs:
@@ -35,7 +35,7 @@ services:
       - internal
 
   signaldb:
-    image: postgres:13-alpine
+    image: postgres:14-alpine
     secrets:
       - signal_db_password
     environment:

compose.telegram.yml

@@ -10,7 +10,7 @@ services:
       - telegram-data:/telegram-data
 
   telegrambridge:
-    image: dock.mau.dev/mautrix/telegram:v0.15.3
+    image: dock.mau.dev/mautrix/telegram:v0.2606.0
     depends_on:
       - telegramdb
     configs:
@@ -40,7 +40,7 @@ services:
       - internal
 
   telegramdb:
-    image: postgres:13-alpine
+    image: postgres:14-alpine
     secrets:
       - telegram_db_password
     environment: